Mercedes has just warned that leakage in coolant pumps causes a fire risk in certain Mercedes vehicles. The bigger problem is that Mercedes can’t issue a recall because the parts needed are not available. It contacted 800,000 owners that could potentially see “risk of a fire that could not be ruled out.”

Right now, there are no Mercedes products in the US that are affected, according to Automotive News. That is mostly due to this being a problem in OM654 and OM656 series diesel engines, which are not sold here. 

Mercedes warns only use vehicles “at a bare minimum”

Once components are available to fix the problem, Mercedes will issue a recall. “In the meantime, the affected vehicle should be driven in a particularly prudent manner and usage reduced to the bare minimum,” says Mercedes in the notification sent to owners. 

It expects that the parts to fix the issue should start showing up to dealers later this month. Mercedes says that the delay in getting the replacement pumps is due to a supply chain issue. There is also a software release involved.

The German newspaper Bild published the letter sent to owners. According to that reporting, the models affected were built between 2017 and 2021. Those involved include the GLE/GLS (167 platform), C-Class (205 platform), E-Class (213 platform), S-Class (222 platform), S-Class (223 platform), E-Class Coupe/Convertible (238 platform), GLC (253 platform), CLS (257 platform) and G-Class (463 platform).

Leaking control valves in the coolant pump create the fire risk

The defective pumps’ drive power can be controlled so that there is a reduction in the coolant delivery rate. This helps to heat the engine more quickly when cold. It also lessens the amount of raw exhaust during cold starts. But the Mercedes control valves for this can leak, with the potential for fire risk. 

The popularity of Mercedes luxury vehicles can be seen in the numbers. It sold almost two million vehicles in 2020 alone. Its most recent recall was for the issue of drivers being able to play video games while driving. This also involved Tesla, but Mercedes was the first to issue a recall for the problem. 

For the past several years Mercedes vehicles sold in the US exceeded 350,000 per year. But the number dropped by almost a third last year due to a combined elimination of some models and supply chain issues. It also faces tough competition from companies like BMW, which surpassed Mercedes sales in 2019. While its sales have increased in some cases, its market share has not.